frv: remove unused cpuinfo_frv and friends to fix future build error

Frv has a macro named cpu_data, interfering with variables and struct
members with the same name:

include/linux/pm_domain.h:75:24: error: expected identifier or '('
before '&' token
  struct gpd_cpu_data *cpu_data;

As struct cpuinfo_frv, boot_cpu_data, cpu_data, and current_cpu_data are
not used, removed them to fix this.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>